A non-reciprocal microwave network is provided that includes an in-line ferromagnetic element [1010] with adjoining polarizing adapters [1002, 1004, 1006, 1008] to achieve directivity via a multi-mode interaction at or near the ferrite to act as new class of 4-port circulator or 2-port isolator, with standard waveguide inputs for assembly in larger networks.

A non-reciprocal microwave network is provided that includes an in-line ferromagnetic element with adjoining polarizing adapters to achieve directivity via a multi-mode interaction at or near the ferrite to act as new class of 4-port circulator or 2-port isolator, with standard waveguide inputs for assembly in larger networks.

A non-reciprocal microwave network is provided that includes an in-line ferromagnetic element with adjoining polarizing adapters to achieve directivity via a multi-mode interaction at or near the ferrite to act as new class of 4-port circulator or 2-port isolator, with standard waveguide inputs for assembly in larger networks.

A non-reciprocal microwave network is provided that includes an in-line ferromagnetic element [1010] with adjoining polarizing adapters [1002, 1004, 1006, 1008] to achieve directivity via a multi-mode interaction at or near the ferrite to act as new class of 4-port circulator or 2-port isolator, with standard waveguide inputs for assembly in larger networks.

A manufacturing method for a waveguide includes forming a core including a first layer and a second layer. The first layer has a top surface including a first region with which a bottom surface of the second layer is in contact, and a second region with which the bottom surface of the second layer is not in contact. Forming the core includes the steps of: forming an initial first layer; forming an etching stopper layer on the second region of the initial first layer; forming an initial second layer on the initial first layer and the etching stopper layer; etching the initial second layer and the initial first layer so as to make the initial first layer into the first layer; and etching the initial second layer until the etching stopper layer is exposed, so as to make the initial second layer into the second layer.

A non-reciprocal circuit device includes: a permanent magnet; a ferrite to which a direct current magnetic field is applied by the permanent magnet; and a plurality of center conductors disposed on the ferrite so as to intersect with one another with being insulated from one another. One ends of the respective center conductors serve as input-output ports, and other ends of the respective center conductors are connected to a ground. Capacitance elements are connected in parallel to the respective center conductors. The permanent magnet includes a first permanent magnet and a second permanent magnet. With respect to the first permanent magnet and the second permanent magnet, directions of respective direct current magnetic fields applied to the ferrite are opposite to each other, and there is a difference between temperature characteristics of respective residual magnetic flux densities.